There is known a welding robot having an arc welding torch attached to a wrist portion of an industrial robot of a vertical articulated type (as referred to Patent Publication 1, for example), as shown in FIG. 3.
In FIG. 3, numeral 1 indicates an industrial robot of a vertical articulated type, and numeral 2 indicates an upper arm portion thereof. A wrist portion 3 is attached to the tip end of the upper arm portion 2. The wrist portion 3 swings on a wrist swinging axis 4 (in directions of an arrow A), and pivots around a wrist pivoting axis 5 (in directions of an arrow B). A welding torch 7 is attached to the wrist portion 3 through a mounting member 6. The welding torch 7 is provided with a shock sensor 8 and a nozzle 9. A wire feeding device 10 is provided at the back portion of the upper arm portion 2, and feeds a welding wire to the welding torch 7 through a conduit cable 11 and a cooling water to the welding torch 7 through a cooling water hose 12, respectively.    Patent Publication 1: JP-A-9-94663